App Tracking Transparency

Also known as: att, ios tracking prompt

The iOS prompt that requires apps to ask permission before tracking you across other apps and sites.

Updated 10 February 2026

Introduced in iOS 14.5, App Tracking Transparency forces every app to show a system prompt before it can access the IDFA or otherwise track the user across apps owned by other companies. The overwhelming majority of users deny.

ATT reshaped mobile advertising by cutting off the main cross-app identifier. It also pushed ad networks toward on-device signal processing (SKAdNetwork) and server-side conversion APIs to survive without a persistent per-user ID.

Related terms

Advertising ID

A resettable per-device identifier iOS and Android give to apps for ad tracking.

Online Privacy

The ability to control what information about you is collected, shared and inferred online.

Tracker

Code, pixel or request that collects information about a user across websites.